Silt accumulator



arch 3,1936. L. c. LASHMET S ILT ACCUMULATOR Filed July 24, 1933 A TTORNEY Patented Mar. 3, 1936 UNITED STATES PATENT OFFICE 2 Claims.

This invention relates to a silt accumulator adapted for various uses, such as an aid in the deflecting of a river, to protect a river bank, to aid in the building up of eroded banks, and of a 5 form which renders the accumulator effective ir= respective of the position assumed thereby. The invention has for an object the provision of a silt accumulator adapted to control the positioning of alluvial deposits in silt-bearing streams.

Another object is the provision of a silt accumulator which is inexpensive in cost of manufac ture, may be assembled or erected by unskilled labor, is efiicient in use and service, is effective for the purpose intended regardless of shifting of 1 the same from various causes from one position to another, and generally superior to devices adapted to or intended for the performance of a similar function, to-wit, the accumulation of silt.

Another object is the provision of a silt accuo0- mulator adapted to act conjointly with other silt accumulators of similar construction and which, regardless of deflection thereof from original zones of installation, still retain their effectivenessin new locations.

Another object is the provision of a silt accumulator so formed and constructed as to perm-it the same to'effectively stop undercutting of banks. As an example of this object, it may be said that the silt accumulators maybe located in a stream having a sandy bottom, and during heavy movement of water resultant upon flood, the accumulators tend to sink and in this manner stop the undercutting of the banks.

Where a stream has cut away a bank,v due to some deflection of the stream, a series of silt accumulators of the character about to be described are effective in aiding in the rebuilding of the bank by alluvial deposits. This method has been found highly satisfactory in many instances and better than placing concrete in the stream for the purpose of deflecting the course of the stream.

It has been determined that the carrying capacity of water with relation to the weight of the particles moved varies as the sixth power ofthe'velocity. It is also known that the settling power of silt varies in accordance with size, weight, shape, temperature and viscosity of the water. The silt accumulator will, therefore, become effective to cause the silt in the stream to 50' settle, providing the silt accumulator is correctly designed and positioned in the moving stream, tothe end that the velocity of the water is reduced on one side of the accumulator or accumulators. Thus, when the flowing stream strikes the accumulators and passes through the same,

it is essential that the accumulator or accumulators, due to their design and position, change the velocity of flow of the fluid. For instance, if the velocity of the stream or current is checked to one-half its previous velocity due to the presence of the silt accumulators, the carrying power of the water is reduced 64 times. If the velocity of the stream is checked one-third, its carrying power is reduced 729 times. Therefore, the importance of correct design in the type of device 15 contemplated by this invention becomes very important, and in actual service, the invention about to be described causes the rapid formation of alluvial deposits.

In practicing the invention, I provide a silt accumulato-r incorporating at least four framing members of substantially equal length crossed intermediate their lengths, the zone of crossing forming a symmetrical geometrical figure in the form of a tetrahedron. Thus, any position as' sumed by the silt accumulator is such that four equidistantly spaced foot portions are provided. The framing members, therefore, substantially constitute the diagonals of a cubical framework.

In addition to the objects above mentioned, the invention consists in the novel and useful provisiomformation, construction, association, and interrelation of parts, members and features, all as depicted in a certain embodiment in the accompanying drawing, described generally, and more particularly pointed out in the claims.

Inthe drawing:

Figure I is a plan view of a plurality of silt accumulators arranged within a stream for the purpose of causing alluvial deposits on one side of said accumulators, and,

Figure 2 is a perspective View of one of the silt accumulators.

Referring to the drawing, in Figure 2 I have shown a silt accumulator I, which includes four framing members 2', 3, 4 and 5. These framing members are adapted to be maintained in a central crossed angular relationship by securing said framing members together in any suitable manner, such as by bolts and nuts 6, spot welding, or the provision of any common means. These framing members are of channel section, as shown at l, and in this connection they may be made of any material such as steel or iron. It will be observed that the framing members are so related at their central crossing zone as to provide at this zone a symmetrical geometrical figure, such as a tetrahedron. This is accomplished by turningthe framing members so that leg portions of certain thereof are at anangle relative to base portions of other framing members. For instance, reference is made to the framing member 2 and the leg 8 thereof which bears against and is secured to the base 9 of member 5 by the means 6. The base It of the member 4 is secured to a leg of the framing 3. The inclining of the base of one member relative to the leg of a further framing member and then pinning the same together provides a framing structure of great strength and one that tends to resist distortion due to the very method of pinning or securing the various framing members in cooperative working relationship. These framing members, in a measure, constitute what might be termed the diagonal members of a cube, and the legs, which would be the terminals or end portions of each framing member, thus provide a structure having six sides. Hence, the device may rest upon any set of four legs and it is evident that if the device should be turned that there would always be four legs for positioning upon a surface.

So far as the inventor is aware, previous silt accumulators are not adapted to be changed in their position or moved from one position to another resultant upon a force acting thereon. As an example, the silt accumulator of this invention may be moved from an original position by a rapidly moving current and still be eifective in a new location, the silt accumulator tending to stabilize itself.

Adjacent the ends of each framing member is an opening or hole designated generally as II and I provide wire bracing I 2 passed through the saidopenings I I of each framing member. This bracing may take any form and may be secured in any manner to the framing members, although for the purpose of convenience, ends of the wire bracing after passage through one of the openings or holes is returnedly bent and twisted upon the main length of the bracing as, for instance, shown' at I3. Diagonal bracing I4 may be provided. In addition to the bracing I2, I may provide further bracing I5 passed through openings in the framing members designated generally as I6, this bracing being looped through said openings and twisted upon the main length of the bracing, as shown at I1. After the bracing is in position and tightened, an accumulator is provided where--.

in the framing members are not likely to be subject to distortion resultant upon rough usage.

Referring now to Figure 1, I have shown the edge of a bank at 20, which acts as one boundary for a stream indicated by an arrow at 2|. This arrow likewise indicates the flow path of the stream. If we assume that it'is desired to build up the bank by alluvial deposit and at a certain portion of the bank 20, several of the silt accumulators may be employed; These silt accumulators are shown in Figure 1 extending at an acute angle relativeto that portion of the bank of the streamwhich is to be built up by silt accumulation or alluvial deposit, to-wit, the portion generally designated as 22.

' To maintain the silt accumulators in position of service, it is necessary that the same be anchored and in Figure 1, I have provided a cable 23 which extends between the several accumulators with both ends of said cable provided with anchors 24 and 25; One anchor, 25, might be in the stream, whereas the other anchor 24 would be received in a suitable pit in the earth formation. Stretching of the cable 23 is a simple matter in that a pit may be dug beneath the anchor 24 and the anchor will gradually settle downwardly within the pit and hence stretch the cable. The

pit may, of course, be filled with earth thereafter. To further assure that the several accumulators will maintain the angularity desired relative to the flow path of the stream, I provide cables 26 secured to certain of the accumulators at one of their ends and with anchors 21 at the opposite ends. These anchors 24, 25 and 21, may be formed of any material such as rock or scrap iron or similar weighty substances. The cable 26 in each instance may be roved about the intersecting zone of the framing members with the end of said cable secured to the main length thereof by a clamp much in the same manner as illustrated in Figure 2. In Figure 2 it will be observed that the cable 23 passes over certain of the framing members and that a short length cable 28 passes under the framing members and is secured to the cable 23 by means of clamps 29 and 30. In place of using the short length two cables 23 in certain installations.

The operation, uses and advantages of the invention are as follows: p 1

Assuming that an installation of silt accumulators has been made in accordance with Figure 1, it will be observed that the likelihood of displacement of the accumulators'is a remote one due to the method of anchoring. It is not absolutely essential that the cables 26 should be at right angles to the cables 23 and in a plurality of accumulators, the angularity of the cables makes little difference. The flow path of the streamis directly against the accumulators and at an angle thereto. In other words, if the flow path of the stream is in accordance withthe arrow 2|, then the imaginary flow path line is at an obtuse angle relative to the cable 23 and the several accumulators. As heretofore pointed out, the efiiciency of the accumulators will depend upon changed velocity of the stream. Hence, it is essential that the velocity of the stream be reduced upon that side of the accumulator or accumulators between which and the bank is to be built up an alluvial deposit. The net-work of. bracing members and the positioning of the framing members is such as to impede the velocity of the stream and result in rapid silt accumulation.

An advantage of the present invention resides in the fact that the framing members may be shipped to the point of installation. in knockeddown form to be assembled by unskilled labor and placed in position under the direction of a foreman. Thus, the cost of labor installation is greatly reduced and the invention gives employment to those least likely to have employment, to -wit, the unskilled laborer.

The foot portions of the accumulators tend to sink in sandy formation and when located in streams having sandy bottoms, effectively stop undercutting and scoring of stream. It is possible to superimpose accumulators if the first set of accumulators settle within the sandy formation. The accumulators likewise may be placed in a stream parallel to the bank for the purpose of preventing erosion of the banks during floods. In the illustration of Figure 1, it is apparent that the alluvial deposits included between the accumulators and the bank will change the flow path of the stream. If, due to heavy flow conditions, such as resultfrom' floods, the anchors should be shifted with resultant slackness in the cables, the accumulators may tend toturn, but inasmuch as the sides are all symmetrical, it is evident that this turning movement will the banks of the cable 28, I may provide fact that if a complete 90 turn is made, four of the feet will again be resting upon the bottom of the stream or adjacent the bank, or if a partial rolling movement occurs when the flood subsides, the accumulator will again assume its original position. The adaptability and fiexibilty of the invention for many uses and purposes-may be readily appreciated by those who are familiar with the problems involved in flood prevention of alluvial streams.

It is obvious that various changes and modifications and variations may be made in practicing the invention in departure from the particular showing of the drawing withoutdeparting from the true spirit thereof as defined by the scope of the appended claims.

I claim:

1. A silt accumulator comprising four channel framing members arranged in crossed relationship intermediate the length of each thereof, the angularities between any adjacent pair of framing members being substantially the same.

2. A silt accumulator including four framing members secured together intermediate their lengths and in the form of diagonals of a cube, and lateral bracing extending between ends of the framing members.

LUTHER C. LASHMET. 

